The invention relates in general to data communication, and more particularly to data communication using a modifiable number of XDSL modems.
A communication server provides access to communication facilities. For example, a communication server having a bank of modems may provide subscriber access to the modems for data communication. A communication server may be associated with its own dedicated network or with an existing network, such as the public switched telephone network (PSTN).
As networks provide greater connectivity and access to information, there is an increasing demand for data communication at higher rates. For example, Internet sessions may require high data rates to accommodate multimedia information. One solution to provide increased data rates replaces existing twisted pair wiring with high bandwidth media, such as coaxial cable or fiber optic links. Other solutions adopt improved transmission techniques using the existing hardware infrastructure. For example, digital subscriber line (XDSL) technology provides higher bandwidth data service over existing twisted pair wiring.
Data rates supported by a single XDSL line may still be inadequate for demands. One solution involving integrated services digital network (ISDN) bundles multiple lines with the same data rate to increase data capacity for a session. However, this known technique lacks the flexibility or intelligence to provide reliable and economical high bandwidth data communication service using XDSL technology.
In accordance with the present invention, the disadvantages and problems associated with data communication have been substantially reduced or eliminated. The present invention provides a communication system that modifies the number of XDSL modems for communicating data in response to loading information and threshold information.
In accordance with one embodiment of the present invention, a communication system for communicating data associated with a session includes a number of twisted pair lines. A first communication device has a number of first XDSL modems coupled to the twisted pair lines. The first communication device communicates data associated with the session using the twisted pair lines. A second communication device has a number of second XDSL modems coupled to the twisted pair lines that communicate with the first XDSL modems. The second communication device determines the number of second XDSL modems for communicating data associated with the session based on loading information and corresponding threshold information of at least one of the second XDSL modems.
In accordance with another embodiment of the present invention, a communication device for communicating data associated with a session using a number of twisted pair lines includes a number of XDSL modems coupled to the twisted pair lines. The communication device also includes an interface and a router for communicating data between the interface and the second XDSL modems. A controller coupled to the XDSL modems and the router receives loading information from at least one of the XDSL modems, compares the loading information to stored threshold information, and determines the number of XDSL modems for communicating data associated with the session.
In accordance with another embodiment of the present invention, a method for communicating data using a number of XDSL modems coupled to a number of associated twisted pair lines includes: determining loading information of at least one XDSL modem; comparing the loading information to threshold information; and determining the number of XDSL modems for communicating data associated with a session in response to the comparison.
Still another embodiment of the present invention includes a method of segmenting a packet of data for communication by a number of XDSL modems, the method comprising: receiving a packet; determining the size of the packet; and segmenting the packet into subpackets based on proportionality factors associated with the XDSL modems to communicate the subpackets.
Important technical advantages of the present invention include a communication device that modifies the number of XDSL modems used in a session. The modification is accomplished by comparing loading information with corresponding threshold information associated with the data rate capacity of the XDSL modems. If the data rate increases to a predetermined percentage (e.g., 80%) of the capacity of an XDSL modem, the communication device requests service from another XDSL modem. Similarly, if the data rate decreases to a predetermined percentage (e.g., 30%) of the capacity of the XDSL modem and more than one XDSL modems are servicing the session, the communication device requests suspension or termination of service from a selected XDSL modem. The communication device may then support a session having a range of data rate needs while optimizing the use of a number of XDSL modems.
Another important technical advantage of the present invention includes the selection of lines based on a variety of characteristics and factors, such as: different upstream and/or downstream data rate capacities, varying times needed to prepare the line for data communication, cost to operate the lines, minimum billing increments for line usage, and other operational parameters. The communication device maintains an activity table to determine status information on twisted pair lines and XDSL modems. In one embodiment, the table contains information on the minimum time each modem should be active for efficient use, the actual time each modem has been in an active state, a priority rank for each modem, fixed and/or adjusted data rate capacity, threshold values to remove or add a modem, and loading information detailing current data rates (e.g., packet rate, bit rate, error rate).
Another important technical advantage of the present invention includes the segmenting of data in proportion to the data rate capacity of active modems. After receiving a data packet from a network, one embodiment of the present invention determines the packet size and then divides the packet into subpackets based on proportionality factors derived from the capacity of active modems serving the session. The communication device addresses the subpackets using virtual circuits supported by a suitable multipoint protocol. Proportionality factors may change dynamically with modifications to the number of modems in active use and adjustments in the current data rate capacity of the modems. Other important technical advantages are readily apparent to one skilled in the art from the following figures, descriptions, and claims.